Separation techniques are widely used in the biological, chemical, and pharmaceutical industries. Most separation technologies rely on one type of interaction between a molecule of interest and a stationary phase comprising a functional modality. For example, the molecule of interest and the functional modality of the stationary may interact via hydrophobic interactions, aromatic interactions, hydrophilic interactions, cation exchange interactions, anion exchange interactions, or steroeochemical interactions.
Enantiomers of a chiral compound differ only in the spatial arrangement of atoms around a chiral center. Enantiomers often act differently from each other in the chiral environment of a living organism. For example, enantiomers may have different pharmacological and toxicological effects and different pharmacokinetic properties. Many of the top selling pharmaceutically active agents are chiral compounds and many are provided as single enantiomers (e.g., Lipitor, Zocor, Plavix, and Nexium). Enantiomers of pharmaceutically active agents may be prepared either by asymmetric synthesis or the separation of racemic mixtures into single enantiomers using a chiral based separation technique. Typically, adequate resolution of the two enantiomers of a chiral compound is only achieved through the use of other types of separation technologies in combination with the chiral based separation technology. As such, the separation and isolation of a single enantiomer may be an expensive and time-consuming undertaking.
What is needed, therefore, is a single separation technology that utilizes several different separation principles. In particular, what is needed is a separation material that separates molecules on the basis of more than one type of interaction.